BL-C2 is a very consistant powder, I would look over other possibilities before ruling out the powder. just to give some ideas check over the gun, loose scope mounts loose stock screws etc. another thing is you obviously have a good load if its shooting sub 1/2 moa if the powder was truly inconsistant then I could see little variences from 1/2 moa to 1 or maybe a little over a moa. but as high as 2+ Id have to say its alot more operator error then the equipment or let alone the powder. after checking everything over and try shooting from a solid rest then maybe you can start ruling out ammo components. good luck